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Small Grains (Harvest) Update

Small grains harvest started in earnest in the Red River Valley last week. Initial yield reports have exceeded my expectations. The test weight and quality also appear to be good with little to no evidence so far of scabby kernels in the harvested grain (and therefore no concerns about DON)

However, there are a number of other issues that concern me and that I like to bring to your attention:

  • Wheat Stem Sawfly (WSS) – The first reports of WSS damage suggest to me that the area with affected fields continues to expand, with WSS having reached the Canadian border in the northern valley.  While you are harvesting, keep on the lookout for severely lodged areas along the edges of the field where you did not see lodging earlier this season. Please inform me if you find the telltale razor-cut straw in these lodged areas.
  • Orange Wheat Blossom Midge (OWBM) – I inspected a grain sample that had a very small percentage of OWBM-damaged kernels. OWBM damaged kernels are small and shrunken and can easily be mistaken for scabby kernels, except for the fact that they do not have the characteristic chalky white appearance. Instead, they have a hallmark divot that housed the developing OWBM larvae. OWBM is an introduced pest that caused substantial economic damage in the mid-nineties. Populations only ever reach economically damaging levels after a few years of delayed planting, this allows the emergence of the female OWBM to coincide with heading and early anthesis of the spring wheat crop. NDAWN includes the very robust OWBM GGD model to predict peak emergence.  It took three years of delayed planting three decades ago. I encourage you to check whether this year’s wheat headed at the same time as the peak emergence of the OWBM females.  That will be informative to gauge the risk of seeing larger populations of OWBM next year.
  • Hessian Fly – Hessian fly is, like OWBM, an introduced pest that generally is an occasional rather than a consistent economic pest in much of the Northern Plains. A lack of overwintering sites is the main reason for the typically low levels of infestation in this area. For Hessian fly to reach economically damaging levels you have to create a green bridge for the pupae to survive the winter and complete its lifecycle to the next growing season. Winter rye, winter barley, quack grass, and ryegrass are among the host of Hessian fly, but it much prefers any kind of wheat (winter, spring, durum). I was contacted after a crop consultant found pupae in a field of spring wheat when he was scouting the field to time a preharvest glyphosate application. He noticed somewhat stunted and leaning tillers and, upon closer inspection, found the pupae in the stems near the soil surface. These pupae will become adults yet this summer, and lay their eggs on volunteer wheat, emerging winter wheat, and emerging winter rye (cover) crops this fall. The Hessian fly larvae will feed, develop and overwinter as pupae on these grasses until next spring when the insects complete their life cycle. Hessian fly can easily be kept in check if the adults cannot successfully find a host to lay their eggs, or when larvae are not allowed to develop into overwintering pupae. That means that volunteer wheat should be controlled before any winter cereals are seeded in the same field and that winter wheat or winter rye (including winter rye for cover crop) should not be seeded before the so-called ‘fly-free’ date that is used in other parts of the US to keep this insect at bay.  In NW Minnesota the fly-free date is approximately September 7-10.
  • Ergot – There is a higher incidence of ergot in both barley and wheat, something we do not see often. The best way to manage and not have it become a source of discounts at the elevator is to not contaminate sound grain during harvest. Field edges are likely to have a higher incidence. Therefore, segregate the grain from the field edges from the remainder of the field. Better yet is to leave the field edges stand and delay harvest as ergot bodies eventually will drop to the ground.  Balance this waiting game with the risk of sprout damage and low Hagberg Falling numbers.
  • Black Point – In the same sample that I found OWBM damaged kernels I also found about 1% black point.  Humid conditions and frequent rains bring on black point. Make sure that you bring down both the temperature and moisture content of the grain as quickly as possible in storage to prevent the problem from getting worse and plan on using a seed treatment next season if you are keeping the grain for seed. And, finally…..
  • Hagberg Falling Numbers (HFN) – While I do not expect this to be a widespread problem at this point, I did receive a call about a low HFN that surprised both the grower and the crop consultant.  After some additional questions and some digging through data, I came to the preliminary conclusion that, in this case, it was likely Late Maturity Alpha-amylase (LMA) as the variety in question was suspect for LMA in 2019.  Bottomline at the moment – contact me if receive a low HFN score and you have no reason to suspect sprout damage.

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